A conventional treadmill is shown in FIG. 12 and generally includes a base 70 and a frame 71 on which an endless belt 72 is connected to the frame 71 so that the users run on the endless belt 72. The endless belt 72 can also be driven by a motor which allows the users to set pre-determined speed of the endless belt 72 to meet different requirements of the users. In order to save space of storage of the treadmill, the length “L” of the base 70 is usually designed to be shorter than the frame 71 and the frame 71 is pivoted relative to the base 70. When the frame 71 is folded to upright position, a securing device is used to hold the frame 71. Nevertheless, the base 70 might be pivoted clockwise about the rear point 700 if the users use too much force and this is because the length “L” of the base 70 is too short. The unstable base 70 could result a dangerous injury to the users.
The present invention intends to provide a folding and supporting device to easily folding the frame of treadmills and the frame can be kept at position by a securing device.